1. Field of the Invention
The present invention relates to a structure for water drainage in a vehicle lamp.
2. Description of Related Art
Japanese Patent Laid-open No. Hei 9-18391, entitled "Lamp for Motorcycle", exemplifies a water drain hole 20 as shown in FIG. 3 of that publication. The water drain hole 20 serves to discharge water and disperse air heated by a bulb in the vehicle lamp. Referring to FIG. 3, an arrow between the outer opening 26 and the inner opening 28 denotes water that may enter into the vehicle lamp when the vehicle is being cleaned or the like. However, this later cannot enter beyond the barrier 18.
In the accompanying drawings, the terms "front" and "rear" denote the directions as seen by a rider on a motorcycle.
FIG. 14 is a side view of a typical motorcycle 100. The motorcycle 100 comprises a body frame 101, a front fork 102, a front wheel 103, a head lamp 104, front indicators 105, 105 (the lamp 105 on the opposite side is not shown), a meter 106, a steering handle 107, a swing arm 111, a rear wheel 112, a tail/stop lamp 113, and a pair of rear indicators 114, 114 (the lamp 114 on the opposite side is not shown). The components 102, 103, 104, 105, 106 and 107 are positioned at the front part of the body frame 101, while the components 111, 112, 113 and 114 are positioned at the rear part of the body frame 101. In FIG. 14, reference numerals 116, 117 and 118 denote an engine, a fuel tank and a rider's seat, respectively.
In case of rain, the rear wheel 112 may splash water as shown by arrows 1 and 2. Furthermore, some of the water splashed by the front wheel 103 may strike the rear indicators 114 as shown by an arrow 3.
FIG. 15 is a cross sectional view of the main part of a conventional front indicator, specifically showing the bottom part of the front indicator 105. The water drain hole structure 120 of the front indicator 105 is similar to that of the foregoing laid-open publication. Therefore, water entering via the outer opening 121 can be effectively blocked by the blockade 122. This structure is effective in protecting the front indicators against water, shown by an arrow 4, splashed from the front side of the moving motorcycle.
FIG. 16 is a cross sectional view of a main part of the rear indicator 114, specifically showing the bottom part thereof. The rear indicator 114 is the same as the front indicator 105, and is oriented exactly opposite to the front indicator 105, i.e. it is turned by 180.degree. on a vertical axis. The same components are used as the front and rear indicators in order to reduce the number of components.
Water splashed by the front wheel (see FIG. 14) enters into the rear indicator 114 via the outer opening 131 of the water drain structure 130, is reversed by the upright wall 132, and reaches the barrier 133. In the event of rain, water tends to go beyond the barrier 133 and enter into the rear indicator 114.
Since a motorcycle usually takes a short period of time to clean, only a little water splashes into the motorcycle, allowing for effective drainage. Therefore, there is no serious problem in such a case. However, on a rainy day, the motorcycle is exposed to rain for a long period of time. Therefore, water tends to enter into the motorcycle more substantially. Hence, there has been a strong demand for improved water drainage structures in motorcycles.